Technical Field
The present disclosure relates to an electrochromic apparatus, an electrochromic element, and a method of manufacturing an electrochromic element.
Description of the Related Art
Electrochromism is a phenomenon in which color reversibly changes as a redox reaction reversibly occurs upon application of a voltage. Electrochromic apparatuses using electrochromism have been actively studied recently with expectation of various applications of electrochromism.
Electrochromic materials used for electrochromic apparatuses include both organic and inorganic materials. Organic materials, capable of developing various colors depending on the molecular structure, are promising materials for color display. Inorganic materials have some difficulties in color development control, however, they are under study with expectation of application to dimming glass and ND filter which can take advantage of low color saturation of inorganic materials.
When considering application of the electrochromic apparatus to a large-scale application, the color development-discharge speed (response speed) will disadvantageously lower because the electrochemical reaction takes a lot of time. On the other hand, the electrochromic apparatus typically uses a transparent conductive film, such as indium tin oxide (ITO) film, as an electrode. There has been an attempt to laminate multiple ITO films to suppress such a lowering of the responsive speed.
To more suppress lowering of the responsive speed, the laminated ITO films should be much thicker. However, increase of the film thickness adversely lowers light transmittance (transparency). It is very difficult to achieve a good balance between low resistance and high transparency since they are contradictory characteristics.